Transient Explorer

What am I looking at?

Every night the Rubin (LSST) and ZTF telescopes image the sky and flag anything that changed since last time: a supernova going off, a star flaring, an asteroid passing through. Each flag is an alert. The Fink broker classifies them, and this site shows what they are and where. Transients the two surveys miss, reported by others to the Transient Name Server, are here too.

Sources

  • ZTF and Rubin: objects the surveys alerted on. Each detection is an alert, with the broker's classification, a reliability score and three image cutouts.
  • TNS: transients reported to the Transient Name Server that neither survey alerted on, among them nearly every bright one south of −30°, which ZTF cannot see. Each detection is a report: the magnitudes reported to TNS (the discovery, and any later ones), each in its reporter's filter, then ATLAS's measurements (c and o bands) for two months while it is brighter than 19. A nova or CV brighter than 14 also gets AAVSO's observers' V for two months: the median of a sample of each night's observations (the tooltip says of how many). Reported by names the surveys (ATLAS, GOTO, Pan-STARRS, …). When ZTF or Rubin later alerts on one, it becomes their object.
  • CBAT: reports on the Central Bureau's Transient Object Confirmation Page that neither the surveys nor TNS have, mostly bright Galactic novae (PNV J…) and dwarf novae in outburst (TCP J…). An object that matches a TOCP entry shows its designation.
  • ASAS-SN: discoveries on the All-Sky Automated Survey for Supernovae's list of transients that nothing above has, mostly cataclysmic variables in outburst (ASASSN-26fg). Each detection is a magnitude the list quotes, in g. An object that matches one shows its ASAS-SN name.
  • A TNS type (SN Ia, Nova, AGN, …) decides an object's class whoever saw it; without one, the broker's label does.
  • An object is active while it has detections in the window. A TNS, CBAT or ASAS-SN object neither ATLAS nor AAVSO measures (fainter than 19, older than two months, or not yet measured) is active only while the window holds its last report, so it leaves the short windows a week later.

Pages

  • Dashboard: how many alerts and objects arrived in a window, what kinds, where on the sky, and the brightest new supernova candidates.
  • Sky: the map. Most of what follows is about it.
  • Objects: the same objects as a table you can sort, filter by the broker's label or TNS type, and page through; click one for its light curve and images.
  • Tonight: a planner for your telescope. Pick your site and telescope, and it lists the supernovae, novae and new objects seen this week that are above your horizon while it is dark and bright enough to see, sorted by when each is best placed, with finder charts, a CSV export and a printable list.

Search

  • An object id (ZTF26abvkmbu, a Rubin id, or the first few characters), a TNS name (SN 2026abc), coordinates (35.71 -4.75 or 02:22:50 -04:45:00, add r=10' for a radius), a deep-drilling field (COSMOS), a class (SN Ia, EclBin) or any name astronomers use (M31).

On the map: zoom to go deeper

  • Whole sky (wider than 20°): a heatmap of how many objects were seen in each patch of sky.
  • Region (1°–20°): a finer heatmap plus numbered badges. The number is the count of objects, the color is their most common class, and a white ring means something new in the last night.
  • Objects (under 1°): one dot per object. A white ring means it was seen last night, and a white center means it has been detected only once so far. Click a dot for its light curve, classification and images.

Drag to pan, scroll or pinch to zoom, or click a badge to zoom into it.

Filters

  • Window: how far back to look, from last night to a year.
  • Active / new: objects detected in the window, or only those first seen in it.
  • Class: most alerts are solar-system objects (asteroids). Pick Non-Solar System to hide them and see what else is out there.
  • Brightness (≤ 20, ≤ 18, ≤ 16): only objects at least that bright. Smaller magnitudes are brighter. An object marked faded was last seen fainter than in the survey's reference image, so it has no brightness of its own and counts only under any mag.
  • History (2+ nights, …): only objects seen on several nights, which filters out one-off artifacts.
  • More filters (Objects only): discovered within some nights, a redshift ceiling, a declination band, a faint limit past your saturation, one-night objects, rising ones, a reporting survey, or those an AAVSO campaign asks for. A view can be named, and its Subscribe panel gives it as a feed, as JSON and as targets for a TOM.

Observing from your site

  • Your site: an observatory from the list, or your latitude and longitude (typed, or Use my location). A position is rounded to half a degree, and the site is remembered in this browser only.
  • Object panel: when the object is up tonight, its altitude through the night with the moon, the next 60 nights, and a Finder chart with a link to AAVSO's comparison stars.
  • Objects: Visible from… keeps what is above your limit in tonight's dark window, with when and how high.
  • Sky: Observer… shades what is below your horizon at a time you pick; the counts do not change.
  • Tonight: Subscribe gives an RSS feed of your setup, one item a night with the picks, once the data through the night before are in (or three hours before dark). A condition (novae, rare types, something brighter than a magnitude) leaves nights without a match out, so a feed-to-email service mails only those. The plan is also JSON, for scripts and robotic telescopes. A feed's address holds your rounded site and setup: a reader or email service you give it to keeps it.
  • Where your data count: the surveys measure their own objects every few nights, but a TNS, CBAT or ASAS-SN object gets only ATLAS's photometry while it is brighter than 19, and AAVSO's nightly V if it is a nova or CV brighter than 14. Unconfirmed marks one reported on a single night in the last two weeks: a detection confirms it, and a deep non-detection is news too. No recent data marks one seen on two or more nights that nothing has measured for four nights or more: a magnitude fills the gap in its light curve. Requested marks one an AAVSO observing campaign asks observers to measure; Campaigns tonight lists the other campaign stars that are up.
  • Report an observation (object panel): where your photometry and spectra go (AAVSO for stars and Galactic novae, TNS for supernovae and novae in nearby galaxies, CBAT for an unconfirmed TOCP entry; an AGN only to AAVSO when VSX lists it, and to TNS when it flares), the name to file them under from AAVSO's VSX, and an AAVSO file formatted from what you type. Nothing is sent from the site; your observer code stays in this browser.

Dark means the sun more than 12° below the horizon (18° if you choose). Positions ignore refraction and precession, a few tenths of a degree: enough to plan, not to point.

Classes

  • SN candidate
  • AGN / nuclear
  • Variable star
  • Solar system
  • Cataloged
  • Unknown
  • Low reliability
  • Other

Data credits

See Data Sources.

Everything here is also available via a JSON API.

The data is refreshed nightly. Every view is a link: on the map the URL records the position, zoom, filters and selected object, so Copy link shares exactly what you see.

Contact us

Objects

Objects
Source
Bucket
More filters
Clear
5,101–5,150 of 221,832 · All objects seen in the 7 nights
Subscribe

A feed of this view: an item for each object that matches, newest discovery first, so a reader shows new matches as they come. Give the view a name under More filters to title it.

The same view as JSON, for scripts (the API; 100 rows a page, with offset):

Its first 100 objects as targets for a TOM Toolkit TOM (Targets → Import Targets), with every name and a link back:

RSSTOM targets (CSV)
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF19abinpsx Unknown18.00 g+0.317.422019-07-032026-10-011062181.00297.4172, -20.6288
ZTF ZTF19abjkvfr Unknownfaded g−0.214.982018-05-242026-10-0137451.00296.2352, -17.7581
ZTF ZTF19abjmaaw Unknownfaded g−0.217.282019-07-032026-10-01911351.00301.3370, -17.9138
ZTF ZTF19abliyty Unknownfaded g−0.218.352019-08-012026-10-0135411.00296.7867, -17.3003
ZTF ZTF19abnnyae Unknownfaded g−0.115.642019-05-042026-10-0113130.99300.2060, -20.4736
ZTF ZTF19abnoacj Unknown19.45 g+0.218.722019-08-052026-10-0146561.00295.4175, -17.1614
ZTF ZTF19abqkcvi Unknown18.44 g+0.117.072019-08-192026-10-0156631.00296.1141, -14.7216
ZTF ZTF19abuvgfj Unknownfaded g−0.314.702018-05-212026-10-0112141.00296.3506, -18.5584
ZTF ZTF19acbqgkn Unknown19.30 g+0.218.652019-10-012026-10-0111111.00298.9396, -20.3469
ZTF ZTF19acekpft Unknownfaded g−0.316.942019-10-122026-10-0159801.00295.1995, -19.1398
ZTF ZTF19aceufhb Unknown16.78 g+0.115.602018-05-242026-10-0120221.00298.7285, -18.0687
ZTF ZTF19acrmbhk Unknown18.39 g+0.317.322018-05-212026-10-0149531.00300.4112, -20.1398
ZTF ZTF19adddjgu Unknownfaded g−0.219.442019-06-052026-10-0147551.00296.2747, -14.6115
ZTF ZTF19addexkf Unknownfaded g−0.618.552018-05-242026-10-01561.00298.5869, -19.1418
ZTF ZTF19addfanw Unknown19.03 g+0.218.022018-09-132026-10-0176991.00297.1702, -14.6437
ZTF ZTF20abaslfs UnknownAT 2020kxt18.56 g+0.618.192020-05-182026-10-011091901.00300.2367, -18.4044Rubin
ZTF ZTF20abasllg Unknownfaded g−0.818.502019-07-032026-10-011223271.00301.3221, -18.3676
ZTF ZTF20abbjhjj Unknownfaded g−0.216.602019-11-182026-10-011021621.00297.4392, -13.7387
ZTF ZTF20abcwsvo Unknown18.94 g+0.318.092019-06-242026-10-01831261.00297.0271, -19.8661
ZTF ZTF20abcxslk Unknown19.79 g+0.219.192020-05-292026-10-019101.00296.7862, -14.4401
ZTF ZTF20abfxleg Unknownfaded g−0.318.882019-07-032026-10-01901301.00300.3115, -18.7807
ZTF ZTF20abgskbo Unknownfaded g−0.219.172020-06-202026-10-0161891.00295.2275, -14.9285Rubin
ZTF ZTF20abmrbik Unknown19.41 g+0.318.592019-06-242026-10-0135431.00298.4416, -20.0816
ZTF ZTF20abnkldw Unknown19.56 g+0.419.312020-05-182026-10-0161821.00294.5820, -18.7841Rubin
ZTF ZTF20abpcigc Unknown18.51 g+0.117.652019-05-042026-10-01991.00294.6350, -13.9919
ZTF ZTF20ackszhi Unknown19.53 g+0.318.722020-10-192026-10-01761261.00295.3650, -20.5438
ZTF ZTF20acnpoot Unknown18.57 g+0.018.572020-10-252026-10-01110.85295.1544, -15.5106
ZTF ZTF20acnprjr Unknownfaded g−0.217.592020-10-252026-10-0163751.00296.9588, -19.5848
ZTF ZTF20acnwfhy Unknownfaded g−0.215.812018-05-212026-10-0119191.00295.7399, -14.6797
ZTF ZTF20acnwfic Unknown17.87 g+0.116.602018-09-162026-10-0117201.00296.2094, -16.3715
ZTF ZTF20acohroh Unknownfaded g−0.316.322018-12-052026-10-011021631.00297.9900, -20.4383
ZTF ZTF21aaxbgyc Unknown19.78 g+0.319.482020-07-212026-10-0128301.00300.3796, -17.7562
ZTF ZTF21aaxbtjj Unknown19.23 g+0.418.652019-06-082026-10-01851291.00294.8658, -15.8810Rubin
ZTF ZTF21aaxlimp Unknownfaded g−0.117.202019-10-012026-10-0145551.00297.2208, -19.1648
ZTF ZTF21aayrpis Unknownfaded g−0.318.352019-06-142026-10-01731031.00295.2664, -16.7485
ZTF ZTF21aazmggj Solar System MPC18.01 g—18.012021-05-062026-10-01111.00295.4361, -17.6013
ZTF ZTF21abaatac Unknownfaded g−0.118.062018-12-042026-10-0142521.00297.7304, -17.4305
ZTF ZTF21abhqtlg Unknown19.11 g+0.318.862019-06-052026-10-0168811.00295.3713, -16.4458
ZTF ZTF21abigvyg Unknownfaded g−0.116.962020-06-202026-10-0123231.00296.2340, -14.5694
ZTF ZTF21abjsecc Unknownfaded g−0.218.622021-07-052026-10-0157691.00296.6758, -18.3183
ZTF ZTF21abkkaxw Unknownfaded g−0.218.832021-07-022026-10-0120231.00296.8911, -15.5979
ZTF ZTF21abndxwf Unknown17.67 g+0.116.652018-05-242026-10-0116181.00295.2452, -15.2131
ZTF ZTF21abybbxg Unknown18.53 g+0.118.412018-05-212026-10-01881.00296.2640, -13.6301
ZTF ZTF21acaaotp Unknown19.01 g+0.118.182021-07-072026-10-0162771.00294.8412, -14.5700
ZTF ZTF21acdtevm Unknownfaded g−0.319.302021-07-022026-10-0150621.00295.4559, -14.4754Rubin
ZTF ZTF21achpvee Unknown17.37 g+0.116.482018-09-162026-10-0127281.00297.3013, -19.5178
ZTF ZTF21achpvfo Unknownfaded g−0.217.432019-06-082026-10-0151641.00296.3228, -18.4954
ZTF ZTF21acqhwrv Unknownfaded g−0.218.792021-11-242026-10-0161801.00299.0749, -19.6745
ZTF ZTF22aajpygb Unknownfaded g−0.218.412022-05-102026-10-01741301.00298.5862, -20.7206
ZTF ZTF22aaouphz Unknown19.74 g+0.218.892021-07-132026-10-0119191.00295.3382, -15.6586